Shahid Chamran University of AhvazJournal of Hydraulic Structures2345-413X3220171201Investigating the vulnerability downstream area of Taleghan dam due to dam failure191343510.22055/jhs.2017.13435ENHamidGoharnejadDepartment of Civil Engineering, Environmental Sciences Research Center, Islamshahr Branch, Islamic Azad university, Islamshahr, IranMahyarAzizkhaniDepartment of Civil Engineering, Environmental Sciences Research Center, Islamshahr Branch, Islamic Azad university, Islamshahr, IranMahmoudZakeri NiriDepartment of Civil Engineering, Environmental Sciences Research Center, Islamshahr Branch, Islamic Azad university, Islamshahr, IranSaberMoazamiDepartment of Civil Engineering, Environmental Sciences Research Center, Islamshahr Branch, Islamic Azad university, Islamshahr, IranJournal Article20170917Due to the immense damage caused by dam failure, especially dams constructed near large cities, it is necessary to consider the breaking phenomena as well as studying and designing different parts of the dam. For this purpose, the hydrograph of the outflow due to dam failure must be identified according to size of the fracture and then flood routing, and flood zone must be determined based on the downstream topography and morphology. The integration of hydraulic models and geographic information system is used to achieve this objective. In this research the effect of breaking Taleghan storage dam due to the slip of a pile of reservoir abutment and the creation of current wave toward the dam body as well as the vulnerability analysis due to the breaking of the dam on downstream lands was studied. At first, Taleghan dam failure for five different scenarios was modeled using the FLOW-3D numerical software and then the geometric data of the river was extracted using the ArcGIS software and modeling the flood due to dam failure was conducted in Hec-GeoRas model. Then, the risk analysis was performed for each break scenario of Taleghan dam. The results indicated that the maximum amount of inundation would occur in Razmian city at an approximate distance of 45 kilometers from Taleghan dam site.https://jhs.scu.ac.ir/article_13435_a19e9aa0b4c91d17a43f5f1b69bda628.pdfShahid Chamran University of AhvazJournal of Hydraulic Structures2345-413X3220171201An experimental study on hydraulic behavior of free-surface radial flow in coarse-grained porous media10211343610.22055/jhs.2018.24185.1059ENAliRajabiDepartment of Engineering Geology, School of Geology, College of Science, University of Tehran, Tehran, Iran.ElhamHatamkhaniDepartment of Civil Engineering, Faculty of Civil Engineering, University of Qom , Qom, Iran.JalalSadeghianDepartment of Civil Engineering ,Faculty of Engineering , Bu Ali Sina University, Hamedan, Iran.0000-0003-1030-5644Journal Article20170915The equations of fluids in porous media are very useful in designing the rockfill and diversion dams, gabions, breakwaters and ground water reserves. Researches have been showed that the Forchheimer equation is not sufficient for the analysis of hydraulic behavior of free-surface radial flows; because, in these flows, in addition to the hydraulic gradient and velocity, the variable of radius is also an independent parameter due to variations in cross section. In this paper, we have used an experimental model to analyze the nonlinear free surface radial flows and to introduce an equation compliant with these flows. This is a semi cylindrical model including a type of coarse grained aggregate which leads the radial flow into the center of a well. Thereafter, the hydraulic gradient was measured on different points of the experimental model by three distinguished methods of difference of successive radii, keeping constant the minimum and maximum radii. An equation, describing the behavior of free surface radial flow, was then proposed by measured data (as regression data) from the laboratory and analysis of the results. Verification of the proposed equation by test data shows that the equation is valid on the established limits of the data.https://jhs.scu.ac.ir/article_13436_949cb8945cf37565aa5f01971ac1300f.pdfShahid Chamran University of AhvazJournal of Hydraulic Structures2345-413X3220171201Three-dimensional numerical modeling of score hole in rectangular side weir with finite volume method22311343710.22055/jhs.2018.24654.1062ENSamiraGhotbiDepartment of Civil Engineering , Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran.AzamAbdollahiDepartment of Civil Engineering , Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran.MehdiAzhdari MoghadamDepartment of Civil Engineering , Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran.Journal Article20171008Local scouring in the downstream of hydraulic structures is one of the important issues in river and hydraulic engineering, which involves a lot of costs every year, so the prediction of the rate of scour is important in hydraulic design. Side weirs are the most important of hydraulic structures that are used in passing flow. This study investigate the scouring due to falling jet from side weir in downstream in side channel numerically. The simulation was done with finite volume method. The comparison of numerical and experimental results of flow fields shows agreement. Results show that from upstream to downstream of side weir located in side channel, scoring is increased and the dimensions of the scour hole in the downstream of the rectangular side weirs increase along it. In fact, at the downstream of the lower edge of side weirs in side channel, scouring has the greatest dimensions; in particular the depth.https://jhs.scu.ac.ir/article_13437_5252b8bfc67ed5e56535e2e8fbc12369.pdfShahid Chamran University of AhvazJournal of Hydraulic Structures2345-413X3220171201Experimental Study of the Effect of Base-level fall at the Beginning of the Bend on Reduction of Scour around a Rectangular Bridge Pier Located in the 180 Degree Sharp Bend32461346110.22055/jhs.2018.24900.1065ENMohammadVaghefiDepartment of Civil Engineering, Faculty of Engineering, Persian Gulf University, Bushehr, Iran.0000-0001-5862-915XMohammadMoghanlooDepartment of Civil Engineering, Faculty of Engineering, Persian Gulf University, Bushehr, Iran.DaneshDehghanDepartment of Civil Engineering, Faculty of Engineering, Persian Gulf University, Bushehr, Iran.ArsalanKeshavarzDepartment of Civil Engineering, Faculty of Engineering, Persian Gulf University, Bushehr, Iran.Journal Article20171018Base-level fall in river beds occurs due to varying natural or unnatural causes. Base-level fall causes the change in the behavior of flow at the location of drop in base-level. In such situations, most of scour occur at the foot of the slope, and slope wall retreats in the upstream direction. This phenomenon widens the wall of the river bank, thus leading to its destruction. The amount of bed topography variations and scour around a rectangular bridge pier with an oblong nose located in the 90 degree angle of a 180 degree sharp bend was studied in this work by generating base-level fall at the beginning of the 180 degree sharp bend, and it was compared with a case without a base-level fall. The results indicated that in the case of base-level fall at the upstream side of the bridge pier, increase in flow depth, as well as reduction in velocity at the area around the pier, is observed, and the maximum depth of scour hole and the volume of scour hole around the pier respectively reduce by 73 and 97% in comparison with those in the case where no base-level fall occurs.https://jhs.scu.ac.ir/article_13461_544067bb9900bc277a14563ed52bdc7f.pdfShahid Chamran University of AhvazJournal of Hydraulic Structures2345-413X3220171201Developing optimal operating reservoir rule-curves in drought periods47611349010.22055/jhs.2017.13490ENSorooshAlahdinDepartment of Civil Engineering, Faculty of Engineering , Shahid Chamran University of Ahvaz, Ahvaz, Iran.HamidGhafouriDepartment of Civil Engineering, Faculty of Engineering , Shahid Chamran University of Ahvaz, Ahvaz, Iran.Journal Article20170809In this study a simulation-optimization model is developed for deriving operation rule-curves in drought periods. To each reservoir, two rule-curves with adjustable monthly levels are introduced dividing the reservoir capacity into three zones between the normal water level and minimum operation level. To each zone of a reservoir and for each month of the year a hedging coefficient is introduced that determines the release from the reservoir. Accordingly, an optimization problem is developed in which the objective is the minimization of water demands deficits in drought and the decision variables are the rule-curves levels and hedging coefficients. For optimization of the problem, a genetic algorithm equipped with a self-adaptive constraint handling strategy is used. To evaluate the objective function and constraints violations, the flexible and widely-used WEAP simulation model is exploited and coupled to the optimization solver. The model is then applied to the Zohreh three-reservoir system in the southwest of Iran and compared to the Standard Operation Policy (SOP). According to the sustainability indices for the system operated in drought, the obtained operating rule-curves are found significantly superior to the SOP. As a result of applying the rule-curves, the modified shortage index (MSI) and vulnerability (extent) of the system are respectively improved by 22% and 28% compared to the SOP. Consequently, the developed policy application resulted in longer periods of deficit (but less severe) as shown by decrease in reliability (5%) and resilience (40%) indices. https://jhs.scu.ac.ir/article_13490_d1fb023114c3211b416412678179952f.pdfShahid Chamran University of AhvazJournal of Hydraulic Structures2345-413X3220171201Finding the Causes and Evaluating Their Impacts on Urmia Lake Crisis Using a Comprehensive Water Resources Simulation Model62771351510.22055/jhs.2018.24762.1064ENAlirezaDarianeDepartment of Civil Engineering, KN Toosi University of Technology, Tehran, Iran.LeilaEamenDepartment of Civil Engineering, K.N. Toosi University of Technology, Tehran, Iran.Journal Article20170812Urmia Lake in northwestern Iran has been facing critical water level shrinkage in recent years with serious environmental consequences. It is expected that with the current trend, the lake will be completely dried out in a few years from now. This study attempts to assess the impacts of human activities on water level fluctuations of Urmia Lake by developing a comprehensive hydrologic simulation model. Model development and calibration was carefully accomplished by utilizing effective water resources management components in the basin. An important contribution was accomplished by properly estimating the agricultural water demand and consumption in the absence of measured data. Result of long-term simulation reveals that excessive water consumption by inefficient and expanding irrigated agriculture is the main reason for Urmia Lake shrinkage. It was found that main reservoirs are only responsible for 23% of current situation. Whereas, 77% of the current crisis has been caused by miscellaneous agricultural water withdrawals in the basin.https://jhs.scu.ac.ir/article_13515_11c6cea5c13f2e70301e9b8223c2654a.pdf